Research shows that marijuana use affects short term memory, but how does it also affect Long Term Memory. How are short and Long Term memories are related. STM holds a small amount of information for a short amount of time. STM is processed in one of two ways, maintenance rehearsal and elaborative rehearsal. Elaborative rehearsal works better when transferring memories into LTM. Elaborative rehearsal is when you relate the information in STM to information you already have stored in LTM. Elaborative rehearsal works because we are processing the information on a deeper level. So in order to form LTM we must first be able to form STMs. How does the use of marijuana affect this process?
According to International weekly journal of science the THC in marijuana weakens the connections, or synapses, between neurons in the hippocampus. The hippocampus is a structure in the Medial Temporal lobe that is crucial for forming new LTMs. This was shown in a case where a person’s hippocampus’ were removed from both sides of the brain to eliminate epileptic seizures but also eliminated their ability to form new LTMs. Smoking marijuana is not as drastic as removing the hippocampus but because the hippocampus contains a lot of THC receptors it does affect the ability to form new LTMs. By the weakening of the connections in the hippocampus memory function is slowed down or stopped in Short and long term memory while on the substance.
Although the memory process is slowed down while using marijuana until recently long term affects affecting memory had not been seen. A study was done on teens who were using marijuana on a daily basis. The people in the study had started using marijuana between the ages of 16 and 17 and used it daily for 3 years. At the time of the study they had been marijuana free for two years. These participants performed 18% worse on long-term memory tests than young adults who had never used cannabis on a long term daily basis. These same participants who scored 18% less also had abnormally shaped hippocampus’. This is one of the first studies to show that correlation between long term memory problems and abnormally shaped hippocampus.
Marijuana is shown now to affect both short and long term memory. Although studies are just starting to be completed and further studies are starting up all over the globe. It is exciting to see what more we can learn about ourselves and the world around us.
Smith, M. J., Cobia, D. J., Reilly, J. L., Gilman, J. M., Roberts, A. G., Alpert, K. I., Wang, L., Breiter, H. C. and Csernansky, J. G. (2015), Cannabis-related episodic memory deficits and hippocampal morphological differences in healthy individuals and schizophrenia subjects. Hippocampus, 25: 1042–1051. doi: 10.1002/hipo.22427
HOW DOES MARIJUANA AFFECT THE BRAIN? (n.d.). Retrieved December 1, 2015, from http://serendip.brynmawr.edu/exchange/node/1808
(n.d.). Retrieved December 1, 2015, from http://www.nature.com/news/how-marijuana-makes-you-forget-1.10152